The invention relates to a vibratory grout consolidator. More particularly, the invention relates to a device which attaches to vertical reinforcing bars within a masonry installation, for vibrating grout contained therein to eliminate air spaces and voids.
Concrete is not only the most widely used building material, but it is the most widely used man-made material on the planet. Among other things, concrete is used to make pavements, foundations, roads, overpasses, parking structures, brick/block walls, and footings for gates, fences, and poles. Perhaps the best reason for its popularity is that it is initially highly formable. Then after hardening through hydration, it has similar physical properties to stone.
In its original semi-plastic state, concrete can be poured into a form of almost any shape, and will generally fill every corner and contour to take the shape of the form. The ability of concrete to flow into a form and fill its shape is known as its “workability”. Often, the presence of large aggregate, and other factors will lower its workability. As a consequence, the concrete will sometimes leave unfilled spaces (voids), and air gaps. Once the concrete hardens, these spaces can weaken the concrete, and make it vulnerable to water infiltration and subsequent freezing and cracking.
Vertically reinforced concrete masonry walls are constructed of blocks which have vertically extending cavities known as “cells”. The blocks are stacked using mortar—like other conventional block walls. In addition, the blocks are reinforced by placing rebar (reinforcement bar) or other bars composed of structural grade materials through the vertically aligned cells of the blocks and then filling the cavities about the bars with grout.
When constructing reinforced masonry walls, then, grout serves an important purpose such that it embeds the rebar that extends vertically within the otherwise hollow masonry blocks. The grout material used for such purposes is essentially concrete, yet often employs smaller sized aggregate.
Vertically Reinforced masonry wall installations are quite vulnerable to workability problems when they are filled with grout. The grout is critical, because it bonds the reinforcement bars to the masonry blocks so that they can act together to resist loads. The scale of the cavities being filled within the blocks, blockages due to mortar joints between blocks, and imperfect alignment between cells as the blocks are stacked, however, provide many opportunities for the creation of voids within the grout. At the same time, such voids can be disastrous when they fail to adequately encapsulate the rebar within the grout. In addition, the presence of a void around a reinforcement bar provides an opportunity for water to collect and exacerbate rust.
It is common practice to vibrate concrete after it is poured, to agitate the slurry so that it removes air and voids while the mixture is still wet. This is often done with a vibrator, which carries an eccentric weight that causes vibrations as it rotates. When the vibrator is immersed within the wet concrete it consolidates the concrete into open spaces and provides pathways for air to escape.
Over the course of many years, various devices have been proposed for vibrating concrete. For example, back in 1929, U.S. Pat. No. 1,770,154 was filed, demonstrating how vibrators were used to eliminate voids and air pockets in forming a reinforced concrete construction having superior strength.
U.S. Pat. No. 6,155,708 to Lindley discloses a concrete vibrator with an offset rotor. Lindley, however, is designed to be immersed in concrete.
United States Patent Application Publication No. 2005/0276156 by Elsten discloses a hand held concrete vibrator that is attached to a common hand drill. Elsten, however, is intended for contacting the outside surface of a wall, and is not suitable for directly vibrating rebar.
U.S. Pat. No. 6,960,011 to Oswald et al. discloses a vibrator for receiving the protruding end of a rebar rod or grid. Unfortunately, Oswald is only suited for attaching over the end of a bar. It cannot be attached at other points on the bar.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.